1. Field of the Invention
This invention relates to optically activated keyboards and, more specifically, to an optically activated keyboard having a light transmitting plunger in each key thereof to provide an indication of the function of each key.
2. Brief Description of the Prior Art
The demand for dynamic key cap labels has resulted in removable templates and other high cost solutions to obtain this result.
Optically activated keyboards of the prior art are exemplified by the above noted patent of Garcia, Jr. as well as by prior art cited therein, bulbs or LEDs behind each key, fiber optics which transmit light to each key and keyboard overlays and templates. In keyboards of these types, the key function has been provided by a symbol formed on the upper surface of the key cap.
A problem with such prior art keyboards is that it is difficult to discern the symbol on the key cap under poor lighting conditions, therefore requiring that the operator memorize the key locations for operation under such low light conditions for operation under such conditions. A further problem arises in the use of the keyboard in military Night Vision systems wherein special wavelength environments are required to provide key legend readability. It is therefore readily apparent that key caps having illuminated symbols thereon are useful and required by the art.